This invention is concerned with a locating mechanism and finds particular, but not exclusive, application in combinations involving a slide displaceable along a track. Such combinations are common in draughtsman's tools where a square is displaceable along a rule and is required to be clamped at a desired location on that rule.
Such a square involves a casting having a slot dimensioned to receive the rule and a pin extending into the slot and having a projection dimensioned to engage in a groove extending along the length of the rule. By retracting the pin, transversely away from the groove, the projection will move into an interference fit with the groove wall and serve securely to lock the casting in position. U.S. Pat. No. 1,532,353 discloses a combination tool in which a miter box is securable on a rule by such a locking mechanism.
Such locking mechanisms suffer from the disadvantage that when the casting or slide is removed from the rule some degree of dexterity is required to manipulate the projection into alignment with the groove to permit reintroduction of the slide or casting onto the rule.